Fuel distributing valve for fuel injection system



March 24, 1959 J. DOLZA ET AL 2,879,046

FUEL DISTRIBUTING VALVE FOR FUEL. INJECTION SYSTEM Filed May 17, 1957 MUM/Iva 22 30am! Off 1.6L

IN VENTORS llnited States Patent 2,879,046 FUEL DISTRIBUTING VALVE FOR FUEL INJECTION SYSTEM John Dolza, Fenton, and Alexander J. Sagady, Centerline,

Mich., assignors to General Motors Corporation, De-

. troit, Mich., a corporation of Delaware Application May 17, 1957, Serial No. 659,969

' 5 Claims. (Cl. 261-23) The present device relates to a fuel distributing valve for a fuel injection system of the type shown generally in copending application Serial No. 608,853, Dolza, filed September 10, 1956. More specifically, the present device represents an improvement in a solenoid controlled coasting fuel shut-off valve of the type shown in copending application Serial No. 648,300, Olson et al.

In a fuel injection system of the Dolza type means is normally provided for shutting off the flow of fuel to the cylinders under vehicle decelerating conditions in order to economize on the use of fuel as well as to prevent the discharge of unburnedhydrocarbons into the atmosphere. In the present device a solenoid controlled fuel distributing valve is utilized which is capable, in addition to shutting off the fuel flow under decelerating conditions, of preventing fuel from draining through the fuel metering system due to any static fuel pressure head developed due to a height dilferential between the nozzles and the fuel metering unit.

The present fuel distributing valve also provides means for initiating the flow of a limited quantity of fuel to the engine nozzles upon the deenergization or opening of the fuel distributing valve upon the termination of its fuel cutoff function. This latter feature is designed to prevent engine stuttering or stalling prior to the resumption of normal fuel flow after coasting fuel shut-off operation.

The details of the present invention as well as other objects and advantages are set forth in the description which follows.

" In the drawing:

Figure 1 is a diagrammatic representation of a fuel injection systemvembodying the subject fuel distributing valve; and

Figure 2 is an enlarged sectional view of the fuel distributing valve.

The fuel injection system functions in the manner set forth 'infthe aforenoted Dolza application and only that much of the system will be described as is necessary to provide the proper environment to an understanding of the subject invention. In general, an air induction passage, is shown at and includes a venturi 14 formed therein. A throttle valve 12 is disposed in the induction passage 10 posteriorly of the venturi 14. A source of fuel under pressure is shown at 16 and is adapted to supply' fuel through a conduit 18 to a metering valve 20. The metered fuel from valve 20 is delivered to a conduit 22 which leads to a fuel distributor 24 having a solenoid controlled fuel cut-off mechanism 26 associated therewith. The metering valve 20 is controlled by a diaphragm linkage mechanism 28 which is actuated in response to vacuum changes in chamber 30 which are variable with the mass of air flow through venturi 14. The venturi vacuum signal is conveyed to the diaphragm chamber 30 through a passage 32. Anadditional vacuum passage 34 communicates with chamber 30 and with the induction passage adjacent the throttle valve 12 to provide a supplemental control force during idle and off-idle operation as "d cribed in Serial No.608j797, Olson.

l lgeiferring to Figure 2, a fuel distributorca'sing is proat 40 and includes a plurality of radially extending pasu ges 42 formed therein and which centrally communicate with a common supply chamber 44. Passages 42 are 2,879,046 Patented Mar. 24,

secured to the fuel distributor casing 40 through suitable stud means 52. An annular solenoid coil 54 is disposed in casing 50. A fuel cut-off valve mechanism 56 is disposed within the solenoid coil 54 and is adapted to communicate at one end with the common supply chamber 44.

A fuel inlet casing 58is suitably secured to cup-shaped casing and includes a counterbored portion 60' with which the fuel cut-oflf valve mechanism is adapted to coact to control the flow of fuel. An inlet passage"'62is formed in casing 58 and communicates with alongitudinally extending passage 64 which opens into the counter,-

bored portion 60 of the casing and defines a circular seat' 66 therewith. I,

The fuel cut-off valve mechanism includes a sleeve 68 fixed at its respective ends to the fuel distributing casing 40 and the fuel inlet casing 58. A valve element 70 is slidably disposed in sleeve '68 and terminates at its lower end in a reduced portion 72 the inner end of which is tapered to coact with the valve seat 66- formed in inlet casing 58. The slidable valve member 70 includes a plurality of radial ports 74 formed therein which communicate at their inner ends with a longitudinally extending passage 76 formed through the slidable valve member. A spring member 78 is seated within the counterbored portion 60 of fuel inlet casing 58 and surrounds the re-' duced portion 72 abutting against a shoulder 80 of the slidable valve element 70 and biases said element in an upper position in which the upper end 82 of the slidable element seats against an annular shoulder 84 formed in distributor casing 40.

A counterbore 86 is formed in the slidable valve element 70 so as to provide a tapered valve seat 88. A valve element 90 is slidably disposed within the counterbored portion 86 of valve element 70 and includes a reduced end portion 92 tapered at 94 to coact with taperedseat 88.

element 70 where it flows upwardly through passage 7 6 to raise valve element 90 off of its seat permitting the fuel to flow between the fluted portions 95 formed therein to the common fuel chamber 44 Where the fuel is equally distributed to the radial passage 42.

Under coasting or engine decelerating conditions soleacid 54 will be energized by any suitable mechanism such as a speed governed switch 96 and a throttle controlled switch 98, as described in the aforenoted Olson application, whereby the slidable valve element 70 will be moved downwardly against the force of spring 78 causing the tapered end of portion 72 to seat against and block the flow of fuel through valve seat 66. 7

As the slidable valve element 70 moves downwardly to cut off the flow of fuel, a portion of the fuel remaining in the counterbore 60 and passage 76 will be forced upwardly around valve element and into the common supply chamber 44.

Having cut off the flow of fuel to the cylinders, acoutinuous flow fuel injection system of the type herein in-' volved normally requires two revolutions of the engine for a given nozzle to furnish the requisite amount of fuel to the corresponding cylinder for any constant rate of operation. Heretofore, this situation, particularly as ag gravated under rapid decelerating conditions, has frequently caused the engine to stall or stutter until the fuel metering system was able to resume the supply of fuel.- to the cylinders. This situation is alleviated in the present mechanism by virtue of the operation of the valve element 90. As noted, when the slidable valve element 70 moves downwardly to cut off the supply of fuel any fuel remaining in the counterbore portion 60 of the inlet casing 58 flows into the common chamber 44. Thus the space above the valve element 90 will be filled with fuel. Thereafter upon the deenergization of the solenoid coil 54 spring, member 78 will move the slidable valve element 70 upwardly under which condition the pressure head of the fuel above the valve element 90 coupled with the weight of the valve element causes the valve to seat and force the fuel from the fuel chamber 44 through the radial passages 42 momentarily supplying fuel to the cylinder fuel supply passages 46. In this way the needs of the engine are satiated until such time as the fuel metering system resumes normal delivery of fuel to the cylinders.

An important additional function is served by the valve element 90. Under normal conditions the fuel nozzles 48 are disposed below the level of the fuel metering valve 20, a pressure will, therefore, obtain on the fuel downstream of the metering system and which pressure is equal to. the head of fuel represented by the height differential noted. Because of this static pressure head, the fuel downstream of the metering valve drains out of, the various passages into the intake manifold proximate the nozzles with the result that such passages must be refilled with a consequent delay in starting. In the present fuel eut-ofi mechanism construction the weight of the valve element 90 is made slightly greater than the static fuel pressure head noted, as a consequence, when the engine is shut off the weight of the valve element 90 will cause the latter to seat preventing the draining or siphoning flow of fuel through the system. In this manner the system remains charged with fuel and ready for easy and rapid restarting. Thus tapered portion 94 of valve element 90 is adapted to seat upon seat 88 against the force of the static pressure head and to be unseated by the dynamic pressure head of fuel upstream thereof. The dynamic pressure head is, of course, created by the fuel source 16. The static pressure head, as noted, is equal to the weight of the column of upstream fuel of the valve 90.

We claim:

1. A fuel distributing mechanism for an internal combustion engine comprising a casing having a plurality of fuel outlet passages formed therein, a common supply chamber adapted to communicate with said outlet passages, a. fuel inlet passage adapted to supply fuel to said common supply chamber, first valve means intermediate said, inlet passage and said common supply chamber for controlling the flow of fuel, means normally biasing said valve means to a position permitting fuel to flow from said inlet passage to said outlet passages, means for closing said valve when it is desired to cut off the flow of fuel to said outlet passages, and second valve means in series with'said first valve means and movable therewith, said second valve means being adapted to seat by gravity when said first valve moves from a closed to an open position to prevent the reverse flow of fuel through said fuel distributing mechanism.

2. A fuel distributing mechanism for an internal combustion engine comprising a casing having a plurality of fuel outlet passages formed therein, a common supply chamber adapted to communicate with said outlet passages, a fuel inlet passage adapted to supply fuel to said common supply chamber, first valve means intermediate said inlet passage and said common supply chamber for controllingthe flow of fuel, means normally biasing said valve means to a position permitting fuel to How from said inlet passage to said outlet passages, means for closing said valve when it is desired. to cut off the flow of fuel toasaid outlet passages, and gravity actuated valve means in, series with said first valve means and movable therewith, said gravity actuated valve means being adapted to seat against the static pressure head of fuel upstream of the second valve.

3. A fuel distributing mechanism for a fuel injection system comprising a casing having a plurality of radially disposed outlet passages formedv therein, a comon fuel chamber centrally communicating with said outlet passages, a second casing fixed to said first casing, a solenoid controlled valve disposed within said second casing, a third casing secured to said second casing, a fuel inlet passage in said third casing, said solenoid controlled valve adapted to coact with said fuel inlet passage to control the flow of fuel to said outlet passages, means normally biasing said valve in an open position permitting the flow of fuel to said outlet passages, said solenoid controlled valve being shiftable to a position blocking the flow of fuel to said outlet passages, and a gravity seating valve element slidably disposed within said solenoid control valve and movable therewith, the flow of fuel through said solenoid controlled valve being sufficient to unseat 1 said gravity seating valve element to permit the flow of fuel therepast.

4. A fuel distributing mechanism for a. fuel injection system comprising a casing having a plurality of radially disposed outlet passages formed therein, a common fuel chamber centrally communicating with said outlet passages, a second casing fixed to said first casing, a solenoid controlled valve disposed within said second casing, a third casing secured to said second casing, a fuel inlet passage in said third casing, a source of fuel under pressure, a conduit communicating said source and inlet passage, said solenoid controlled valve adapted to coact with said fuel inlet passage to control the flow of fuel to said outlet passages, means normally biasing said valve in an open position permitting the flow of fuel to said outlet passages, said solenoid controlled valve being shiftable to a position blocking the flow of fuel to said outlet passages, and a gravity seating valve element in series with and slidably disposed within said solenoid control valve and movable therewith, said gravity seating valve element adapted to be unseated by the dynamic pressure head and seat against the static pressure head of fuel in said inlet passage.

5. A fuel distributing mechanism for a fuel injection system comprising a casing having a plurality of radially disposed outlet passages formed therein, a common fuel chamber centrally communicating with said outlet passages, a second casing fixed to said first casing, a solenoid controlled valve disposed within said second casing, a third casing secured to said second casing, a fuel inlet passage in said third casing, means. for supplying fuel under pressure to said inlet passage, said solenoid controlled valve comprising a tubular sleeve, a cylindrical member closed at one end and opened at the other, said member being slidably disposed in said sleeve, a longitudinal passage in said sleeve terminating in the open end thereof, the closed end of said member being of reduced crosssection and terminating in a tapered valve portion, a plurality of radial ports in the reduced portion of saidmember, said ports communicating the space between said sleeve and said longitudinal passage, the tapered end of said slidable member being adapted to coact with said fuel inlet passage to control the flow of fuel through said mechanism, a counterbore formed in the open end of said slidable member, a valve seat formed in said counterbore, a valve element slidably disposed in said counterbore and including a tapered end portion adapted to seat Within said counterbore seat, said valve element adapted to be unseated by the dynamic fuel pressure head acting thereon, said valve element being adapted to seat by gravity against the static fuel pressure head acting thereon.

References Cited in the file of this patent UNITED STATES PATENTS 

